The invention relates generally to inspection systems and methods, and, more particularly to, electromagnetic resonance frequency inspection systems and methods for estimating material properties of a part.
Components such as aircraft engine parts can be protected from developing microcracks by stressing the surface layer of the part using shotpeening. Very briefly, shotpeening involves bombarding the surface of the part with small spherical media called shot. Each piece of shot striking the surface imparts a small indentation to the part. In order for the indentation to be created, the surface of the part must be yielded in tension. Further, below the surface, the material tries to restore its original shape, thereby producing a hemisphere of material that is highly stressed in compression. Monitoring of material properties of shotpeened parts is desirable to determine how long the part can be used before it needs to be re-shotpeened. For example, it is desirable to monitor the shotpeen residual stress depth profile of the part to assess the need for re-shotpeening of the part.
Typically, a destructive evaluation of the shotpeened part is performed to estimate the material properties of the part. However, this technique makes the part unusable and therefore requires replacement of the part. In other applications, certain shotpeened parts may be re-shotpeened at select time intervals without assessing the need for re-shotpeening the part.
Accordingly, it would be desirable to develop estimation techniques that provide accurate estimation of material properties of a part. Particularly, it will be advantageous to develop a technique for accurate estimation of the material properties of a shotpeened part without damaging the part.